What is CFA drilling?
CFA. CFA (continuous flight auger) is a single pass piling method, where a continuous flight auger is used to drill to depth. During the grouting phase, concrete is pumped through the auger simultaneously with the extraction of the auger from the ground.
How are CFA piles installed?
CFA piles are constructed by rotating a hollow stem continuous flight auger into the soil to a designed depth. Concrete or grout is pumped through the hollow stem, maintaining static head pressure, to fill the cylindrical cavity created as the auger is slowly removed.
What are SFA piles?
The “Sectional Flight Auger” or SFA is an auger bored ‘replacement’ pile with soil extraction and pumping of concrete under pressure. The piles is formed by means of helical screw (auger) with a hollow stem bored into the ground to design depth.
What are augered piles?
A piling technique; a Continuous Flight Augered Pile is a non-displacement pile used in difficult ground conditions. The drilling process is suitable for use in dense layers and is resistant to ground water or unstable soil conditions.
Are CFA piles friction piles?
Continuous flight auger piles are used for places with unstable soil conditions and high level of ground water table. These piles can be terminated in clays, granular soils, in soft rock or can be taken to hard load bearing strata i.e. bearing type of piles or friction piles due to their continuous operation.
What augered piles?
What is Rotary Bored Piling?
Rotary bored piling (RBP) uses a machine, called a piling rig, with specially designed drilling tools including buckets and augers to remove soil and rock. These tools are used to bore into the ground repeatedly, removing spoil as the pile is progressed, until the design depth is reached.
How do you make a cased CFA pile?
Cased CFA piles are formed by drilling to the required depth using a string of hollow stem continuous flight auger drill string, encased within a string of segmental casing of equal length. They rotate independently and in opposite directions to assist spoil transport upwards.
Which is better a CFA pile or an auger cast pile?
Auger Cast Pile Types Driven Piles vs. CFA Foundation Auger Cast Piles Noise and vibration due to pile driving are minimized. CFA piles eliminate splices and cutoffs. Soil heave due to driving can be eliminated when
What are the effects of using CFA piles?
CFA piles generate soil spoils that require collection and disposal especially if it is contaminated. Construction Sequence – Drilling Effect of Over- Excavation using CFA Piles
How does the belpile cased CFA system work?
Belpile now utilise the latest in cased CFA technology to overcome the commonly encountered installation problems outlined above. The cased CFA system utilises a double rotary drilling head and involves housing the augers inside rigid steel casing.